Personal audio devices, including wireless telephones, such as mobile/cellular telephones, cordless telephones, mp3 players, and other consumer audio devices, are in widespread use. Such personal audio devices may include circuitry for driving a pair of headphones or one or more speakers. Such circuitry often includes a power amplifier for driving an audio output signal to headphones or speakers.
In some personal audio devices, changes in a modulation index of a signal processing circuit may lead to signal distortion, such as a signal being clipped by a supply voltage providing power to the signal processing circuit.